A comprehensive review on basic approaches to improve pharmaceutical solubility

Abstract

Solubility improvement of pharmaceutical substances can be quite intriguing, especially if they belong to BCS class-II new chemical entities. Solubility and bioavailability are two important concerns of pharmaceutical scientists which hinders the choice of variety of dosage forms of the active substances. Many new chemical entities which are lipophilic in nature and have great therapeutic advantage over contemporary may not be formulated into a dosage form. This review focusses on the basic approaches to improve the solubility around which many advanced techniques can be developed. Traditional approaches of improving solubility are to increase the surface area exposed to body fluids, dispersion or inclusion of lipophilic solutes into hydrophilic carriers. Nanotechnology has emerged as a revolutionary approach in mid-1980’s in this area of study. The approaches can be a building-up approach through self-assembly, or precipitation of bits from larger units. Whatever is the approach chosen, ultimate result would be nanosizing of drug particles and there would be an enormous amount of surface energy available. Improper channeling of accessible free surface energy can root the nanosized elements to impulsively cumulate into further thermodynamically steady state.